The modern store — be it a grocery or a Gap — is ingeniously designed to pry you apart from your money. Stores are so good at “suggesting” and “reminding” you to buy extra stuff that up to a full 70 percent of all grocery-store purchases are unplanned.

All too often, you’re spurred into spontaneous expenditures because tricky merchandising has soothed your senses, manipulated your emotions and impaired your judgment. Salvage your savings by better recognizing and resisting the environmental prods described here.

Sales Ploy:

The frontal assault, a.k.a. “eye level is buy level”

The most expensive items with the fattest profit margins are displayed in the most eye-catching, easy-to-grab locations.

Counter Punch: Look around! And not just on the lowest and surrounding shelves: Certain product groups may be “split,” with the new candy-flavored toothpaste in one prominent display and the store’s inexpensive generic brand four aisles over.

And don’t assume that items promoted in displays, placed at the end of the aisle or advertised in circulars are on sale. Often, “that’s not true,” says Peter Fader, Ph.D., a marketing professor at the Wharton School of the University of Pennsylvania. Do what your mama said — shop around — and compare the cost per ounce or per pound between brands. If you find math difficult, tote a calculator to the store.

Sales Ploy:

Scent technology

It’s no coincidence that so many stores smell heavenly. Seductive scents excite the deepest, most primordial parts of our brains. “Good smells make us start salivating, and when we salivate, we buy more stuff,” explains Paco Underhill, author of Why We Buy.

Counter Punch: “Never shop when you’re hungry or tired!” advises Underhill. Inhaling tempting odors when you’re famished increases salivary output to irresistible levels, lowers your resistance and leads to rash decisions. If you can’t avoid shopping on a tapped-out tummy, pack a banana or low-fat power bar in your purse and eat it before entering the store: An ounce of power bar prevention is better than buying a dozen unnecessary doughnuts.

Sales Ploy:

The sound of music

When you like a store’s music, you feel more comfortable, Underhill explains. The more comfortable you feel, the longer you stay. And the longer you stay… you guessed it: the more you’re likely to spend.

Counter Punch: Remind yourself: It’s OK for me to have a great time in this store and not buy anything! Also, before you head for the register, ask yourself: Am I buying this because I really, truly need it and will use it? Recreational shoppers are most vulnerable to music-influenced splurges, so if you shop for pleasure, institute a personal policy always to wait a week before buying any item not in your budget.

Sales Ploy:

Manipulating your own flesh and blood

Stores place products kids are crazy for where they are likely to see them. You know what follows: A bunch of wallet-walloping wheedling and high-pitched, heartrending pleas.

Counter Punch: “There’s no upside to shopping with kids,” notes Fader, so park them elsewhere if you can. But if shopping with the little beggars is unavoidable, put them to work — and teach them fiscal wisdom by using Fader’s brilliant lesson plan.

Kids predictably will plead for pricey name brands they’ve seen advertised. When Junior tries to slip the frosted flakes with a cartoon tiger into your cart, tell him you’ll split the savings if he can locate a similar item in the store for less money. “Let them stumble upon it themselves,” counsels Fader. On your next trip, you won’t have to pay a finder’s fee: They will ask you to buy their own “discoveries.”

Sales Ploy:

Big baskets

Many stores offer huge shopping carts — much larger today than their predecessors of yesteryear. Why? Providing extra cart space is just one less obstacle when you decide whether or not to add extra items to your cart, Fader explains.

Counter Punch: Never shop without a list — and stick to it! If you’re darting in for just a few things, skip the pushcart for a handbasket or no basket at all.

Sales Ploy:

Sales

Two for one! Buy one, get one free! Sixty percent off! Free gift with purchase! Rebates!

Counter Punch: Don’t believe the hype. “If the product is so great, why do you need an incentive to buy it?” Fader inquires. In many cases, these “sales” are deceptive. The store may be trumpeting that you get 24 oz. of detergent at the 20-oz. price, “but the regular package was 24 oz. and they shrunk it,” Fader notes.

Sales Ploy:

Obscured or unavailable price information

Unavailable price information and products placed out of your reach force you into contact with a salesperson whose job it is to “romance you into buying it,” notes Underhill. A similar principle is at work in department and clothing stores that only have mirrors outside the dressing room: Step out to see what those pants look like and you are assailed by a hailstorm of flattery and compliments from the salesclerk.

Counter Punch: Repeat, The salesperson is not my friend, until you believe it. Remind yourself that she’s probably working on commission, and bring a real friend along if you’re vulnerable to sales pressure. If you’re really a wimp, steer clear of high-pressure places that don’t have mirrors mounted in the dressing rooms or don’t display prices.